TThe Treatment Section continues its long-term projects to improve treatment for substance dependence through behavioral, pharmacologic, and combined behavioral and pharmacologic interventions. In addition to an innovatively designed randomized clinical trial of clonidine that we just published in American Journal of Psychiatry, we are continuing to study individual differences that might be important for personalized treatment and for patient-treatment matching. Interest in the medical uses of cannabis has led the suggestion that smoked cannabis alleviates symptoms of opioid withdrawal. To evaluate that hypothesis, we analyzed data from the methadone-taper phase of a clinical trial we had conducted in 116 outpatient heroin and cocaine users (of whom 46 were also cannabis users) who had elected to undergo a 10-week taper. The main outcome measures were weekly urine screens for cannabinoids, plus every-two-week assessments of opioid-withdrawal symptoms. Opioid-withdrawal scores did not differ overall between users and nonusers of cannabis. In a lagged analysis in the 46 cannabis users, there was a slight (not statistically significant) indication that weeks of higher opiate-withdrawal symptoms preceded weeks of cannabis use. Even if this finding is taken to suggest self-medication with cannabis, a lagged analysis in the other temporal direction showed no indication that cannabis use predicted lower opiate-withdrawal symptoms the next week. These findings persisted in sensitivity analyses controlling for each of 17 potential confounds. Our findings do not provide clinical evidence for smoked cannabis as a reducer of opioid-withdrawal symptoms, at least in the context of a methadone dose taper like the one we used. This finding may remove one rationale for medication development using cannabinoids to treat opioid withdrawal, but leaves other rationales intact. Finally, we continue to develop Geographical Momentary Assessment (GMA), an approach to measurement and understanding of the relationships among mood, drug use, and environmental exposure to psychosocial stressors in participants daily travels. GMA is largely a descriptive technique, but we remain committed to transforming description into intervention. For example, we have shown that electronic-diary studies can provide amazing insight into the daily lives of substance abusers during treatment and data that are sensitive to behavioral changes during even brief periods of abstinence. The technologies that enable us to collect data on drug use, craving, and stress in the field may also be used for delivery of treatment in the field, perhaps in response to the patients movement toward previously identified triggers.